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By R. I. Jaffee, H. R. Ogden, D. J. Maykuth

IN THE past year, Jaffee and Campbell&apos; and Finlay and Snyder2 reported on the mechanical properties of titanium-base alloys, some of which were in the same ranges of composition as are covered in this paper. In this paper, evidence confirming that given by Finlay and Snyder on the effects of carbon, oxygen, and nitrogen on titanium will be presented; and, in addition, new data will be given on the effects of these elements on the flow properties and phase transformation of titanium. Materials and Preparation of Alloys The preparation and general properties of iodide titanium have been adequately described elsewhere.&apos; , As-deposited iodide titanium rod, prepared at Battelle, of Vickers hardness less than 90 was employed as the base metal in the present work. This was the same material as that used by Finlay and Snyder.2 The probable analysis reported by them for standard quality metal holds here also: N 0.005 pct, 0 0.01 pct, C 0.03 pct, Fe <0.04 pct, A1 <0.05 pct, Si <0.03 pct, and Ti 99.85 pct. Carbon was added in the form of flake graphite supplied by the Joseph Dixon Crucible Co. Oxygen was added in the form of c.p. grade TiO, powder, produced by J. T. Baker Chemical Co. Nitrogen was added in Ti3N4 powder, supplied by the Remington Arms Co. Individual ingots weighed 7 or 8 g. Carbon, oxygen, or nitrogen was added by placing the corresponding powder in a capsule made from as-deposited iodide titanium rods and melting the capsule with the balance of the charge. The charge was are-melted with a tungsten electrode on a water-cooled copper hearth under a partial vacuum of very pure argon (99.92 pct minimum). Melting was practically contamination free. Vick-ers hardness increases of less than 10 points were normal for unalloyed iodide titanium control melts. Nitrogen analyses of are-melted iodide titanium showed a nitrogen content of 0.005 pct, about the same as is present in the as-deposited rod. No tungsten pickup was found in a melt of iodide titanium analyzed for tungsten. Weight losses in melting nitrogen-free alloys were very small and varied consistently from nil to 0.015 g (0 to 0.2 pct). This permitted the use of nominal composition for these alloys. Chemical analyses made for carbon, which can be analyzed conveniently by combustion methods, justified this procedure. Where nitrogen was added, considerable splattering took place. Here it was necessary to analyze for nitrogen by the Kjeldahl method. The ingots were hot rolled at 850°C to about 0.045 in. thick. After hot rolling, the strips were descaled by mechanical grinding, and then given a cold reduction of 5 to 10 pct to insure a uniform thickness throughout the length of the specimen. The edge strips and the tensile strips were annealed in a vacuum of 1x10-4 mm Hg pressure for 3 1/2 hr at 850°C and furnace cooled. Methods of Investigation Hardness Measurements: At least five Vickers hardness measurements were taken using a 10-kg load on each sample in the following conditions: (1) top and bottom of each ingot, (2) top and bottom surface of as-rolled and annealed sheet, and (3) on cross-section of annealed sheet and all quenched specimens. Tensile Tests: Tensile tests were conducted on Baldwin-Southwark testing machines having load ranges of 600 or 2000 lb. Tests were made on 1-in. gauge-length specimens, 3 1/4-in. overall length, 1/2 in. wide, 0.040 in. thick, with a reduced section 1 1/4 in. long and 0.250 in. wide. Two SR-4, A-7 strain gauges, one mounted on each side of the specimen, were used to measure the strain over a limited range to determine the modulus of elasticity. After the modulus of elasticity readings had been taken, load vs. strain readings were taken, using only one strain gauge, at increments of 0.0001 in. until the yield points were passed and then at 0.001-in. increments to the limit of the strain-gauge indicator (0.02 in.). Strain readings above 0.02 in. per in. were taken every 0.01 in., using dividers to measure the strain between the 1-in. gauge marks until the maximum load had been reached. Crosshead speed, when using the SR-4 gauges, was 0.005 in. per min, and, when using dividers, 0.01 in. per min. Flow Curves: Flow curves were determined using the true stress-true strain data obtained during the tension test. The usefulness of this type of information has been dealt with very adequately elsewhere by L. R. Jackson,&apos; J. H. Hollomon,6 and many others. Flow curves of true stress vs. true strain could be converted to the more conventional cold-work curve of 0.2 pct offset yield strength vs. percentage of cold reduction by means of the transformation, 1/1 = 1/1-R, where R is the fraction reduction in cold working. Thus, the true strains corresponding to percentage reduction can be calculated, and the 0.2 pct offset yield strengths scaled off the — 6 curve by taking the true stresses corresponding to the values of 6 + 0.002 strain. Heat Treatment: For the transformation studies, the alloys were heat treated in a horizontal-tube furnace using a dried 99.92 pct argon atmosphere, and quenched into water. Essentially no contamination was found after several hours of heat treatment at temperatures up to 1050°C. Metallography: Specimens were prepared in the

Jan 1, 1951

By Edward Keller

(New York meeting, February, 1912.) IN a paper, entitled A Uniform Method for the Assay of Copper Material for Gold and Silver,1 A. R. Ledoux invited the assayers of this country to contribute to a symposium, in which the results of their assays of given samples of copper-matte and metallic copper would be made comparable. This symposium 2 appeared about one year thereafter; and through it and its discussion, first became generally known the fact that the ,gold-yield by the all-fire method of assaying is usually higher than by the so-called combination (wet and dry) method, in which nitric acid is employed as a solvent for the copper. In the publication alluded to, the supposed cause of gold-losses in the latter method was declared to be the solvent action of copper nitrate, or of the reduction-products of the nitric acid, upon the gold. Up to a very recent date, gold has been held to be insoluble in pure nitric acid. (The solvent action of any chlorine present in the nitric acid must here properly be disregarded as belonging in the realm of carelessness. Among later allusions to this topic, W. R. Tan Liew 3 ascribes the solution of the gold in the combination-assay entirely to the action of nitrous acid at the high reaction-temperature of copper and nitric acid ; F. B. Flinn 4 a believes the low result in gold to be due exclusively to mechanical losses-finely-divided gold penetrating through the filter-paper-but presents no experimental data confirmative of this belief; and 0. Pufahl 5 attributes the solubility of the gold in some coppers to the presence of selenium-a view which appears to be shared by many as- 1 Trans., xxiv., 575 (1894). 2 Trans., xxv., 250 (1895). 3 Engineering and Mining Journal, vol. lxix., No. 16, p. 469 (Apr. 21, 1900). 4 Engineering and Mining Journal, vol. lxxxvii., No.11, p. 569 (Mar. 13, 1909). 5 Lunge, Chemische Technische Untersuchungs Methoden, vol. ii., p. 229 (1900).

Jul 1, 1912

By Emery R. Hayhurst

SILICOSIS has been described in a report of the American Public Health Association as a disease due to breathing air containing silica, characterized anatomically by generalized fibrotic changes and the development of miliary nodulations in both lungs, and clinically by shortness of breath, decreased chest expansion, lessened capacity for work, absence of fever, increased susceptibility to tuberculosis (some or all of which symptoms may be present), and by characteristic X-ray findings. ... The disease is divided arbitrarily into first, second, and third stages for convenience of description and possible compensation purposes. At least two distinct types of silicosis are recognized, acute and chronic. The acute form was reported as early as 1713, when a British patent for grinding flint by wet methods was granted because the dry powdered material "proved very destructive to mankind, so much that any person, ever so healthful, working in that business cannot possibly survive over two years."

Jan 1, 1936

By B. J. Klee

What is the economic basis for direct, continuous particle size measurement and control? First, precise grinding control is necessary to achieve and maintain a specified recovery and throughput. Second, throughput and recovery are direct functions of particle size-and these two factors control the economic performance of the ore concentration process. Third, only size-based control using a particle size and percent solids monitor (PSM) has achieved the necessary precise control. Recovery, throughput and cost can be accurately measured for various concentrator operating conditions if particle size is closely controlled. From such data the economic results of different particle size grind points can be analyzed. This will reveal the best combination of recovery and throughput to meet objectives established by financial management. Predictable, repeatable response to set-point selection is essential if the projected profitability of the mill is to be reached.

Jan 11, 1976

By W. Bonfield

The microstrain characteristics of a polycrystal-line Cu 1.9 wt pet Be precipitation-hardening alloy have been determined for various conditions of aging. The friction stress remained constant for all the conditions investigated, whereas the microscopic yield stress (the stress to produce a plastic strain of 2 x 10-8 in. per in.) and the three-stage stress-strain curve in the microstrain region were sensitive to changes in dislocation and precipitate distribution. Correlations between the measurements of microplasticity and electron-nzicroscope observations of substructure are considered. ALTHOUGH the macroscopic mechanical properties of Cu 1.5 to 2.0 wt pet Be precipitation-harden ing alloys were established&apos; in some detail, there has been no previous investigation of the nature of microyield-ing in these alloys. This paper describes a high-sensitivity extensometer determination of microplasticity in polycrystalline Cu 1.9 wt pet Be, in which the friction stress, the microscopic yield stress (the stress to produce a plastic strain of 2 x 10-6 in. per in.), and the rate of strain hardening in the micro-strain region were measured for various conditions of precipitation. The structural changes accompanying aging in this alloy were examined using transmission electron microscopy, a study which differed from previous investigations as, in order to minimize grain boundary precipitation effects,&apos; the solution-treated alloy was cold-rolled to 40 pet reduction prior to aging. Hence the extent of recovery and recrystalliza-tion, as well as the variation of precipitate morphology and distribution, were assessed. From these results possible correlations between the microstrain characteristics and the observed precipitate and dislocation structure are considered. EXPERIMENTAL PROCEDURE The material investigated was a commercial copper beryllium alloy (Berylco 25), which had a com- position of 1.9 wt pet Be and 0.2 wt pet Co. The alloy was solution-treated at 800°C, quenched in water, and then cold-rolled to 40 pct reduction. Tensile specimens of gage length 1 in. and rectangular cross section of 0.18 by 0.06 in. were prepared from the solution-treated, cold-rolled material and aged for 15 min, 2, 24, and 100 hr at 315°C and 24 hr at 425°C to produce a range of precipitate structure. The hardness values associated with these conditions are listed in Table I. It can be seen that a maximum value is obtained after 2 hr at 315oC, which decreases with continued time at temperature to a minimum after 24 hr at 425°C. For comparison some as-solution-treated specimens were also aged for 2 hr at 315°C. The specimens heat-treated to a given condition were examined in two ways. First, the nature and distribution of the precipitate and dislocation structure was characterized using transmission electron microscopy. Thin foils were obtained from the specimens by electrolytic polishing in a 30 pet nitric acid-alcohol solution at -20oC, and were examined in an RCA EMU 3 electron microscope. Second, the mi-croplastic behavior of the specimens was measured with a Tuckerman strain gage, using the load-unload technique previously described2, 3 to determine the friction stress, the microscopic yield stress, and the variation of plastic microstrain with stress. RESULTS 1) Structural Changes During Aging. a) Annealing Processes. The solution-treated, cold-rolled Cu 1.9 wt pet Be had an irregular dislocation-cell structure,

Jan 1, 1968

By Julian Nardi

Pumping solids through a pipeline is not new but until very recently other means of transportation were cheaper. Many proposed pipelines for transporting solids, while technically feasible, have not been attractive enough to warrant the financial risk involved. In some instances, the difference in transportation cost was negligible. In others, the threat of pipeline competition resulted in a slashing of rates on existing transportation to the point where a pipeline could no longer be justified. In others, a competitive product was cheaper. FIRST IN PLACERS The earliest record of solids being transported in a pipe was in the late 1850s in California placer mines. Water under pressure was used to force gold-bearing gravel up through a pipe, from 30 to as much as 55 ft, to a point where it could be discharged into a flume or sluice.

Jan 9, 1959

By Zárate G. E.

Practical and statistical considerations concerned with the sampling, sample preparation and chemical analysis of precious metal ores are reviewed. The principal requirements related with the characteristics of sample cutter, sample preparation, equipment and methods are discussed. The main errors introduced in the different stages of the sampling systems are defined. The application of statistical techniques to evaluate these errors to determine the ore grade variation and to design the number of increments needed to get an accurate assay are presented. Finally, results obtained with the application of this method to gold and silver ores are analyzed and some recommendations are given.

Jan 1, 1984

By R. L. Sebastian

ALUMINUM&apos;S war history is the record of a successful race to expand facilities fast enough to meet the multiple increases in military requirements, principally for aircraft. From the beginning of the war program in 1940 through 1942, requirements estimates were repeatedly lifted to new high levels, and plans for increasing capacity had to be constantly revised. In 1943, basic metal supply caught up with and exceeded requirements, and by 1944, the surplus of primary production was large enough to force reduction in output and plant closings. In the past two years, ingot capacity has been ample, though periodic critical shortages have been experienced for a few fabricated shapes as a result of sudden shifts in demand. And now with all controls lifted we are faced with surplus capacity, surplus stocks, and surplus scrap. In 1938 the Aluminum Co. of America was the only U. S. producer of primary

Jan 1, 1946

By A. Tonejc, A. Bonefacic

As can be seen from the phase diagram A1-W1 the equilibrium solubility of tungsten in aluminum is practically nil at room temperature. By quenching from the liquid state (50,000°C per sec), Varic, Burov, and Kolesnicenko2 obtained A1-W solid solutions up to 0.15 at. pct W. The quenched alloys were in the form of foils, 0.2 to 0.3 mm thick. Considering the results of Duwez and Willens,3 it is obvious that this thickness, which makes impossible a sufficiently rapid quenching, was the main reason for the relatively low content of tungsten dissolved in aluminum found by varic.2 he present note shows that the metastable solubility of tungsten in aluminum can be appreciably extended in aluminum-rich A1-W alloys. The quenching technique and the procedure employed for the preparation of the alloys have been described previously.475 The resulting quenched flakes varied in thickness from 1 to 20 µm from experiment to experiment. However, the measurements of the lattice parameters were carried out only with flakes thinner than 5 µm. The areas of quenched flakes were between 0.1 and 15 mm2. The quenched flakes were placed into a 0.3-mm glass capillary tube which was then mounted in a 114.6-mm-diam Debye-Scherrer camera. Straumanis asymmetric film position and nickel-filtered CuKa radiation were used. The lattice spacings were computed taking X(CuKa1) = 1.54050A for resolved and ?(CuKa) = 1.54178A for unresolved doublets. All specimens were rotated at room temperature, 26o +2°C. The lattice parameters were estimated from extrapolation against the Nelson-Riley function. It was estimated that the error in the lattice parameter of the measurements on a single film lies within +0.0004A for lower and about +0.001A for higher concentrations of tungsten. The lattice parameters of the metastable solid solutions A1-W are plotted vs the concentration of tungsten in Fig. 1 together with the parameters measured by previous investigators.&apos; Each point of the present measurements represents a determination of the lattice spacing on different quenched flakes, for a given concentration of tungsten. With experimental accuracy, the lattice parameters of the metastable solid solutions fall on the straight line passing through the already known data.&apos; As estimated from the uncertainties in the lattice spacings of the solid solutions, the alloys were homogeneous within 0.1 at. pct W. The solubility of tungsten in aluminum-rich A1-W solid solutions obtained by a very rapid quenching technique is increased to about 0.95 at. pct W. This value is 6 times greater than the amount known up to now. -he lattice parameters of the resultant aluminum solid solutions with higher concentrations of tungsten than 0.95 at. pct W did not remain constant AUGER electron spectroscopy has been used to clarify the role of impurities in the embrittlement of AISI 3340 steel. Analysis of fracture surfaces has shown that the embrittled condition is correlated with appreciable antimony segregation at grain boundaries. The low temperature (400" to 600°C) temper embrittlement of low alloy steels containing various combinations of Cr , Ni , Sb , Mn , P , Sn , and As has been examined extensively for many years. General reviews of the area have been made by McMahon1 in 1968, LOW&apos; in 1959, woodfine3 in 1953, and Holloman4 in 1946. Recent work by Low, Stein, Turkalo, and LaForce5 has done much in separating the alloy and

Jan 1, 1970

By H. L. Marcus, P. W. Palmberg

As can be seen from the phase diagram A1-W1 the equilibrium solubility of tungsten in aluminum is practically nil at room temperature. By quenching from the liquid state (50,000°C per sec), Varic, Burov, and Kolesnicenko2 obtained A1-W solid solutions up to 0.15 at. pct W. The quenched alloys were in the form of foils, 0.2 to 0.3 mm thick. Considering the results of Duwez and Willens,3 it is obvious that this thickness, which makes impossible a sufficiently rapid quenching, was the main reason for the relatively low content of tungsten dissolved in aluminum found by Varic.2 he present note shows that the metastable solubility of tungsten in aluminum can be appreciably extended in aluminum-rich A1-W alloys. The quenching technique and the procedure employed for the preparation of the alloys have been described previously.475 The resulting quenched flakes varied in thickness from 1 to 20 µm from experiment to experiment. However, the measurements of the lattice parameters were carried out only with flakes thinner than 5 µm. The areas of quenched flakes were between 0.1 and 15 mm2. The quenched flakes were placed into a 0.3-mm glass capillary tube which was then mounted in a 114.6-mm-diam Debye-Scherrer camera. Straumanis asymmetric film position and nickel-filtered CuKa radiation were used. The lattice spacings were computed taking X(CuKa1) = 1.54050A for resolved and ?(CuKa) = 1.54178A for unresolved doublets. All specimens were rotated at room temperature, 26" +2°C. The lattice parameters were estimated from extrapolation against the Nelson-Riley function. It was estimated that the error in the lattice parameter of the measurements on a single film lies within +0.0004A for lower and about +0.001A for higher concentrations of tungsten. The lattice parameters of the metastable solid solutions A1-W are plotted vs the concentration of tungsten in Fig. 1 together with the parameters measured by previous investigators.&apos; Each point of the present measurements represents a determination of the lattice spacing on different quenched flakes, for a given concentration of tungsten. With experimental accuracy, the lattice parameters of the metastable solid solutions fall on the straight line passing through the already known data.&apos; As estimated from the uncertainties in the lattice spacings of the solid solutions, the alloys were homogeneous within 0.1 at. pct W. The solubility of tungsten in aluminum-rich A1-W solid solutions obtained by a very rapid quenching technique is increased to about 0.95 at. pct W. This value is 6 times greater than the amount known up to now. -he lattice parameters of the resultant aluminum solid solutions with higher concentrations of tungsten than 0.95 at. pct W did not remain constant AUGER electron spectroscopy has been used to clarify the role of impurities in the embrittlement of AISI 3340 steel. Analysis of fracture surfaces has shown that the embrittled condition is correlated with appreciable antimony segregation at grain boundaries. The low temperature (400" to 600°C) temper embrittlement of low alloy steels containing various combinations of Cr, Ni, Sb, Mn, P, Sn, and As has been examined extensively for many years. General reviews of the area have been made by McMahon1 in 1968, LOW&apos; in 1959, woodfine3 in 1953, and Holloman4 in 1946. Recent work by Low, Stein, Turkalo, and LaForce5 has done much in separating the alloy and

Jan 1, 1970

By James Aston

INDICATIVE of the practical importance of the achievement of James Aston , recipient of the Robert W. Hunt Medal for 1930, is the following prosaic item from the financial columns of a recent issue of a New York newspaper. "According to private advices from Pittsburgh, production costs of the A. M. Byers Co. for 1929 were reduced about $5 a ton by the use of the Aston process for making wrought iron pipe. A greater saving is anticipated for 1930, when more of the company?s requirements will be produced by the new method."

Jan 1, 1930

By W. Armstrong Price

INVESTIGATION by German chemists during the World War showed that particles of iron oxide form rapidly in iron pipes carrying hydrogen gas under pressure when the gas contains small amounts of water. Under these conditions, the gas frequently exploded when expanding into a dirigible. The explanation of the explosions lies in the building up of a charge of static electricity in the flow just beyond the orifice and the ignition of the gas by a spark accompanying discharge of the electricity. Friction between the moving particles and the pipe generated the electric charge, which was manifested by a pale blue glow formed in the flow at pressures above two atmospheres. In one experiment, this glow, at eighty atmospheres, extended for a distance of forty to fifty centimetres, but did not ignite hydrogen and air mixtures until the charge was col-lected by a conductor and discharged across a gap between electrodes placed at the side of the column of gas. Autoignition did not occur when this discharge was effected at a distance from the gas column, nor if the gas used was thoroughly dried and free from impurities. The electric charge has been studied by placing various wire and screen conductors in the outcoming stream of gas, Guest having summarized these experiments. The application of these conclusions to fires in petroleum and natural gas issuing uncontrolled from wells is made in the following paper, citing the ignition of a wild gas well in Texas.

Jan 1, 1936

By T. R. A. Davey

IN 1947 the author became interested in the fundamental aspects of the desilverizing of lead by zinc, conducted some experimental work, and searched the technical literature for all available fundamental data. Since then a revival of interest in the subject in Europe resulted in the appearance of quite a number of papers. It became evident that it would be more profitable to collect together and examine thoroughly the results of various workers, than to attempt to duplicate the experimental determinations. There are many inconsistencies in the various publications, and it is opportune to review at this time the present status of knowledge on the Ag-Pb-Zn system. There is also a need for a clear description, in fundamental terms, of the various desilverizing procedures. This paper is presented in four sections: 1—There is an historical review of the origins of the Parkes process, of the results of many attempts to find a satisfactory fundamental explanation for the phenomena, and of the modifications proposed to date. 2—A diagram of the Ag-Pb-Zn system is presented. This is believed to be free of obvious inconsistencies or theoretical impossibilities, although thermodynamic analysis subsequently may reveal errors. 3—The fundamental bases of the various desilverizing procedures, which have been used up to the present day, are described; and a new method is suggested for desilverizing a continuous flow of softened bullion in which the bullion is stirred at a low temperature in two stages producing desilverized lead at least as low in silver as that from the Williams continuous process and a crust which, on liquation, yields a very high-silver Ag-Zn alloy. 4—A suggestion is made for the revival of de-golding practice, following a recently published account which does not seem to have attracted the attention it deserves. The terms "eutectic trough" and "peritectic fold" as used in this paper are synonymous with "line of binary eutectic crystallization" and "line of binary peritectic crystallization" as used by Masing.&apos; The German literature on ternary and higher systems is rather extensive and a fairly general system of nomenclature has arisen, whereas in English usage the corresponding terms are not as well established. For this reason the meanings of terms used in this paper, together with the equivalent German terms, are given as follows: 1—Eutectic trough—eutektische rinne: line at which a liquid precipitates two solids S1 and S2 simultaneously. If the composition of a liquid which is cooling reaches this line, it then follows the course of this line until a eutectic point is reached, or until all the liquid is exhausted. The tangent to the eutec-tic trough cuts the line joining S1S2. 2—Peritectic fold—peritektische rinne: line at which a solid S1 and a liquid L transform into another solid S2. If the composition of a liquid which is precipitating S1 reaches the line, on further cooling only S2 is precipitated. The liquid composition moves from one phase region (L + S1) into the other (L + S2), and does not follow the course of the boundary. The tangent to the peritectic fold cuts the line S1S2 produced nearer S,. 3—Liquid miscibility gap, or conjugate solution region—mischungslucke: the region within which two liquid phases coexist in equilibrium over a certain range of temperature. A system whose composition is represented by a point in this region comprises one liquid at high temperature; then as the temperature is progressively reduced, two liquids, one liquid and one solid, one liquid and two solids, and finally three solids. 4—Liquid miscibility gap boundary—begrenzung der flussigen mischungsliicke: the line along which the surface of the miscibility gap dome, considered as a solid model, intersects the surrounding liquidus surfaces. 5—Tie lines—konoden: lines joining points representing the compositions of two liquids, a liquid and a solid, or two solids, in equilibrium. In binary systems the only tie lines customarily drawn are those through invariant points, e.g., through the eutectics of the Pb-Zn and Ag-Pb systems, or the various peritectics of the Ag-Zn system, as in Figs. 1 to 3. In ternary systems it is desirable to draw sufficient tie lines to indicate the slopes of all possible tie lines. 6—Ternary eutectic point—ternares eutektikum: point at which liquid transforms isothermally to three solids, S1, S2, and S Such a point can lie only within the triangle 7—Invariant peritectic (transformation) point— nonvariante peritektische umsetzungspunkt: (a) — On the miscibility gap boundary, the point at which two liquids and two solids react isothermally so that L, + S, + L, + S2. (b)—On the eutectic trough, the point at which a liquid and three solids react iso-thermally so that L + S, + S2 + S3. Such a point must lie on that side of the line joining S,S which is further from S,. (c)—A further possibility, not found in this ternary system, is that the point is at the intersection of two peritectic folds when the reaction concerned is L + S, + S, + S Historical Introduction Karsten discovered in 1842 that silver and gold may be separated from lead by the addition of zinc.2 Ten years later Parkes used this fact to develop the well known desilverizing process which bears his

Jan 1, 1955

By N. H. Emmons

(Canal Zone Meeting, November, 1910.) AN interesting development of copper blast-furnace construction has been brought about in adapting the blast-furnace to be a "burner" for sulphuric acid making. When the Tennessee Copper Co. first decided to construct an acid-plant, the standard type of brick-top furnace, supported by structural steel, was the only one in use at this plant. All the tests for temperature and strength of gas had been made on these furnaces, and had been satisfactory. When, however, the acid-plant was put on the flue, and the flue had to have a damper put in it to force the gas into that plant, troubles began. The furnaces were fairly tight, and for a few months the work was quite satisfactory., Fig. 1 shows the old type of furnace-top used at the start. It was soon found that this top would not stand the temperatures, particularly when dampered back, as was necessary to force the gas into the Glover towers. The structural steel, of which the furnace skeleton was constructed, warped and twisted so badly that it was not safe to use the furnaces. This effect is shown by Fig. 2, which is a photograph of old No. 4 furnace, after the brick-work had been removed. It became apparent that a new type of top was necessary and the engineering force was started oil the design of a new furnace-top, with the result that a low top, with brick-lined flues at each end below the feed-floor, leading to the main concrete dust-chamber, was constructed. This furnace, No. 7, is shown in Fig. 3. The charging-doors are made of cast-iron sections, three sections to a door, and three doors to a side. A door to the furnace was made of cast copper, but the heat was so great that the copper bent readily, due to the jarring of its * General Manager, Tennessee Copper Co.

Feb 1, 1911

By Jack F. B. Silman

Proving up any large, open pit ore deposit by normal exploration drilling under the best of conditions is a noteworthy accomplishment. But, when adverse conditions preclude standard drilling methods, and the same end result is achieved by a relatively new and little known type of drilling, special comment is in order. Three major problems confronted exploration drilling at the Questa molybdenite mine of the Molybdenum Corporation of America-sampling, terrain and time. Surface and underground longhole drilling provided the needed solutions, thus making the greatest single contribution to an exploration and development program that was successful in proving a major, open pit molybdenum deposit.

Jan 5, 1965

By H. LIVINGSTONE LMAN

A GOOD DEAL of information concerning flotation has come out during the patent litigation of recent years, and the legal situation has cleared considerably, to the satisfaction of Minerals Separation, Limited. Hence, Mr. H. Livingstone Sulman, one of the originators of the successful process of that company, felt at liberty to explain, on Thursday, Nov. 20, his experience and his views in a "Contribution to the Study of Flotation," before the Institution of Mining and Metallurgy. He did not give technical details. He dealt with the physical problems, so simple, as he remarked, that he had wanted 96 pages to express his views. He presented much data, partly new and based on observations of his own, bearing upon the very complex flotation phenomena in an instructive wav and made frequent references to the valuable researches especially of Prof. Edwin Edser and Mr. Emil Hatschek.

Jan 1, 1920

By J. F. Myers, S. D. Michaelson, F. C. Bond

This work was undertaken with the object of collecting plant data on rod milling, making laboratory tests on representative samples of the various ores, and arriving at a basis for comparing the relative efficiencies of different mills operating on widely different materials and under varying conditions. These efficiencies consider only power consumption and do not include the other elements of operating costs. The over-all economic efficiency may be quite different from the consumption efficiencies with which this paper is concerned. It is hoped that these collected data will be of value in indicating the most favorable conditions of rod-mill operation. Operating-plant data on 14 different installations from II plants throughout the United States and Canada were collected, and laboratory tests were made on samples of these ores. The plant rod mills were all operated wet, and either in open circuit or with circulating loads so small as to be negligible. Data were obtained on one roll-crushing operation at the Utah Copper Co., for comparison. The rolls were operated wet in closed circuit with 10-mesh vibrating screens, and with a high circulating load averaging about 600 pct. This particular roll operation can be considered as a model of efficiency. The collected plant data are necessarily incomplete in some instances. Each ore was assigned a code number, and the name and location corresponding to the code number are listed in Table I when permitted. The power data in every instance refer to motor input. Net power was reported by the operator for samples 1-30 and 1-45, and this was increased by 20 pct to compensate for motor losses and power factor. The plant rod-mill data are listed in Tables 2 and 3. In Table 2 the speeds are calculated on the basis of partly worn rod-mill liners 2 in. thick. Where D

Jan 1, 1949

By AIME AIME

INSTITUTE members attending the Annual Meeting in New York who want to see one of the mining engineers&apos; newest aids, photoelastic stress analysis, are due for an interesting afternoon on Thursday, Feb. 15, when open house: will be held at the Columbia University mining laboratory. Information as to the direction and distribution off stresses in mine structures, which has been developed by Professor Bucky, associate professor at the Columbia School of Mines, and David Sinclair, research assistant, is useful in the design of pillars and in the placing of openings relative to working places such as gangways and haulage levels.: This work has been sponsored during the last ten years by the Engineering Foundation.. It is fully reported in T. P. No. 1140.

Jan 1, 1940

The Iron and Steel Committee of the American Institute, of mining and Metallurgical Engineers held a joint session with the American Foundrymen&apos;s Association during the Annual Meeting of the Institute in February, 1928, for the purpose of discussing blast-furnace operations and the character of pig iron and castings. Dr. Richard Moldenke presided. H.. H. Sweetser, who was named on the program as the presiding officer of the session, was unable to be present, but sent a letter in which he said: " The meeting we had here last year and the meeting held in Chicago last June showed a desire on the part of blast-furnace men and users of pig iron to get the facts regarding the influence on castings made from pig iron produced in blast furnaces under varying conditions of temperature, mixture and local furnace operations. It has been my hope that at this Round Table we might he able to formulate a series of tests that, would give us the desired information. "Several independent blast-furnace investigations have. been, and still are being, carried on in different sections of the country. The furnaces investigated include a southern furnace, a middle-west furnace, a western furnace and a Chicago district furnace. The results so far show distinct characteristics for each of the four furnaces. It is possible that a furnace in the eastern part of the United States would be different from all the others. "It is hoped that a plan of action can be worked out at your meeting today whereby the IT. S. Bureau of Mines will be able, to carry on more extensive work in connection with the research departments of the different iron and steel companies and the big consumers of pig iron. "No one group can get all of the, information but if the different investigations can be coordinated it will he possible for us to (Iran. conclusions regarding the effects of varying conditions in blast-furnace practice on the pig iron produced and the castings made there from." DISCUSSION R. Moldenke, Watehung, N. J.—I was across the -water this summer and saw some of those interested in an investigation of this kind. &apos;I&apos;hey told me that in Germany, where they had a joint committee of blast-furnace operators and foundry-

By C. C. Herrick

The vapor pressure of indium has been measured by the torque-effusion technique, as a function of temperature between 1102o and 1422oK. For liquid indium, the vapor pressure (in atmospheres) can be represented by the equation -R In P = 5.782 x104/T - 25.29from 1000o to 1422oK. Extrapolation yields a calculated normal boiling point of 2329°K and a heat of vaporization at 298 oK of 58.09 kcal per mole by the third-law method and of 58.39 kcal per mole by the second-law method. Calculations indicate that the free-energy functions of Hultgren are to be preferred to those of Guruich. BECAUSE of the potential uses of liquid metals, it is important that convenient experimental methods be developed which will lead to a sufficient body of thermodynamic data so that reasonable estimates of properties of liquid metals can be made. Indium is particularly well-suited to investigation, since it remains liquid over a long temperature interval, it alloys readily, suitable containers for it are easily procured, and relatively few investigations of its thermodynamic properties in the region above 1000°K have been made. PREVIOUS RESEARCH The first determination of the vapor pressure of indium was made by Anderson,&apos; using the Knudsen method and silica-lines stainless-steel cells. Kohlmeyer and spandau2 determined the normal boiling point, and a mass-spectroscopic investigation has been made by Lyubimov and Lyubitov.3 (Unfortunately, only an equation representing the data of the latter investigators has been available to us.) Hultgren et al.4 and Gurvich5 have published discordant tables of the free-energy functions for indium. EXPERIMENTAL METHOD The torsion-effusion principle has been described amply in the literature.8,7 With this method, one observes the angular deflection induced by effusion of vapor from a multihole effusion cell which is suspended from a filament producing a small rotational restoring force. The pressure within the effusion cell can be computed from the relation ziaifiai where k is the torsion constant of the filament, 6 is the observed angular deflection, and ai, fi, and qi are the area, force factor, and moment arm of the ith effusion orifice. The force factor f is analogous to the Clausing factor,&apos; and corrects for the reduction in effusive force attributable to the finite geometry of the effusion orifice. Schultz and Searcy&apos; have tabulated the force factors for various tube geometries. EXPERIMENTAL APPARATUS The physical arrangement employed in this study is shown in Fig. 1. The furnace elements are six Globar heat rods with 15-in. hot zones. Temperature is maintained to * 1°K by a Beck mechanism driving two 26-amp Powerstats in parallel. A Pt (Pt, Rh 10 pct) thermocouple serves as the sensing element. Four inner tubes act as vibration isolators; the air pressure required for maximum isolation was determined empirically, and is maintained by a solenoid valve. The tungsten fiber, 9 by 0.002 in., is joined to an 0.008-in. tungsten wire or graphite rod via a machined lightweight chuck.

Jan 1, 1964